The use of sweet sorghum vinasse for biogas production (5 posts)

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  • Denis Picco said 3 years, 7 months ago:

    1st April, 2011

    Dear all,
    dear members
    one of the most important steps on the bioethanol production starting from sweet sorghum biomass is the energetic exploitation of the residual biomasses, as the bagasse and the vinasse.
    The use of bagasse for the stem and power production, partially used in the bioethanol plant, will be treated in other topics.
    In this topic I would like to talk about the use of the vinasse for the biogas production through the anaerobic digestion (fermentation). At the end of the distillation process, there is a large amount of vinasse production, with specific chemical and physical characteristic. Starting from this characteristics it is possible to think about the co-digestion of the vinasse with other type of biomasses, as manure, sewage, bagasse, etc., with good final results.
    The incomes from the biogas production and the related power generation are really important for the economical sustainability of the model.
    There is different experiences about the use of vinasse from sugar cane in the biogas production. I would like to ask you if you could insert some details and information in this forum about your experiences in this. In the next days I plan to insert some evaluation about the quality of the sweet sorghum vinasse and the potential uses for the biogas production.
    Thanks,

    Denis Picco

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  • Oscar Leòn said 3 years, 7 months ago:

    Dear Denis,

    good topic. Really important. At the end, the vinasse is one of the most important “problems” of the bioethanol production. In Europe, for example, this “waste” can be used, after concentration and drying, for animal feed, but, when the price of the animal feed is not enough to cover the concentration and drying cost… the biogas is the alternative.
    Of course, considering the high COD and BOD of this waste, we need to treat it before discharge it. If we obtain energy in this treatment.. perfect and if we obtain energy and fertilizers.. better.

    Best regards

    Oscar

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  • monteiro said 3 years, 7 months ago:

    Dear Dennis, dear all:

    This is definitely an interesting issue, as it may be the key for the feasibility of many Sweet Sorghum-based ethanol projects.
    However, in my opinion there may be two basic problems to sort out. First of all, the characteristics of the vinasse throughout the year. Secondly, the enormous ammount of vinasse produced per liter of ethanol.
    Actually, I’m convinced that a SS ethanol plant will have to work with different forms of SS all over the year - fresh stalks, when available (maybe from August to October, in Southern Europe countries); and SS concentrated juice (or “syrup”) during the rest of the year).
    We shouldn’t then expect that the chemical and/or biochemical composition of the vinasse will always be the same. This may have have several consequences, not just in terms in the biogas production efficiency, but also of the co-products of the plant, especially the biofertilizer.
    This problem could be minimized if it is assumed that the vinasse will always be mixed with a stable biomass source, like, for instance, SS bagasse silage (like the Germans are doing with maize silage).
    Finally, the second issue: the huge ammount of vinasse produced per liter of ethanol, which is difficult to make compatible with a medium-sized biogas plant. In the end of the day, may be the energy produced with the biogas plant is going to be necessary to solve the problem of such a big ammount of effluents, perhaps helping to dry out an important part of this by-product.
    In my opinion, there is a lot of work to do in this side of the SS ethanol production scheme. May be some project could be launched based on ideas like these I just expressed. Are there any partners interested?

    José Monteiro (from Portugal)

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  • Denis Picco said 3 years, 7 months ago:

    Dear Oscar and José,
    dear all
    in our “Early manual”, which concern the sweet sorghum biomass valorisation for the bioethanol production, we talk about an hypothetical EU model, that consider biofuel only one, and definitively not the most important, energetic final product: power and termic energy complete the potential energetic exploitation of this kind of biomass. At the end our is an integrated model, in which you could choose the best way to transform your sweet sorghum biomass in different energetic products.

    Biogas, or biomethane, is one of this energetic products. Our model consider the large amount of vinasse production during the year and its valorisation in a biogas plant in which you add cow sewage. May be in the next weeks we can inset more data about the size of these plants.
    At this moment we are studying in an Italian Project called MULTISORGO, also this aspect. In this project, which is a sort of application of the Sweethanol project, we have planned different studies in our biogas pilot plant. We have planned the use of vinasse, fresh bagasse, ensiled bagasse and sewage mixed in different ways.
    I think that until the end of the year we could have some interesting data about this.

    Of course we are interested in a development of a EU project related to the by-products exploitation, not only in the energetic way. I think we could have a look for the different opportunities in the EU programs and try to build a project.

    Denis

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  • Mario A. Rosato said 3 years, 6 months ago:

    Dear all
    rather than conventional biomethanization, which is perfetly feasible, I see large potential for the research of this substrate for biohydrogen production by dark fermentation. Or a double process, composed by dark fermentation plus conventional digestion, in order to obtain high heat value biogas. The combined dark fermentation plus bamboo plantation is a net carbon sink . Download full article http://ideas.economist.com/sites/default/files/imce/Economist%20InnoCentive%20Challenge%20Final%202%2018%2011.doc

    Nothing prevents the bamboo being used for both 1st and 2nd generation ethanol production.
    I would like to develop a FP7 project on this subject. There’s little or no experience with ethanol from this plant. Anybody interested in joining?

    Mario

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